Fig. 2: The arbitrary shape scattering elimination theory is based on the 2D hologram.
From: Soft Metalens for Broadband Ultrasonic Focusing through Aberration Layers
A The schematic diagram of a 2D hologram by applying the acoustic time-reversal mirror techniques based on wave equation with reciprocity, one monopole source is placed at the right side of the aberration layers, the phase accumulation at the hologram plane can be calculated by phase change of the monopole source and aberration layers; B phase profile comparisons between SML and acoustic hologram; C phase change rate shows consistent tendency between SML and acoustic hologram while slightly shift happens in the reverse point of pressure phase.
